GIGABIT ETHERNET CONSORTIUM

Transcription

1 GIGABIT ETHERNET CONSORTIUM Clause G/5GBASE-T PMA Test Suite Version 1.2 Technical Document Last Updated: March 15, , 5 and 10 Gigabit Ethernet Testing Service 21 Madbury Road, Suite 100 Durham, NH University of New Hampshire Phone: (603) Fax: (603) University of New Hampshire

2 The University of New Hampshire TABLE OF CONTENTS TABLE OF CONTENTS... 2 MODIFICATION RECORD... 3 ACKNOWLEDGMENTS... 4 INTRODUCTION... 5 GROUP 1: PMA TRANSMITTER ELECTRICAL SPECIFICATIONS... 7 TEST MAXIMUM OUTPUT DROOP... 8 TEST TRANSMITTER NONLINEAR DISTORTION... 9 TEST TRANSMITTER TIMING JITTER TEST TRANSMITTER POWER SPECTRAL DENSITY AND POWER LEVEL TEST TRANSMIT CLOCK FREQUENCY GROUP 2: PMA RECEIVER ELECTRICAL SPECIFICATIONS TEST BIT ERROR RATE VERIFICATION TEST BIT ERROR RATE VERIFICATION TEST ALIEN CROSSTALK NOISE REJECTION GROUP 3: PMA IMPEDANCE SPECIFICATIONS TEST MDI RETURN LOSS TEST MDI IMPEDANCE BALANCE APPENDIX: TEST SETUPS , 5 and 10 Gigabit Ethernet Testing Services 2 Clause 126 PMA Test Suite v1.2

3 March 25, 2016 v1.0 Mike Klempa Curtis Donahue The University of New Hampshire MODIFICATION RECORD Initial Draft Release July 8, 2016 v1.1 Mike Klempa Updated to D3.2 standard, fixed alien test bandwidth, added new setup diagrams March 15, 2017 v1.2 Hayden Haynes Updated to IEEE Std bz -2016, fixed miscellaneous text and formatting errors. 2.5, 5 and 10 Gigabit Ethernet Testing Services 3 Clause 126 PMA Test Suite v1.2

4 The University of New Hampshire ACKNOWLEDGMENTS The University of New Hampshire would like to acknowledge the efforts of the following individuals in the development of this test suite. Mike Klempa Curtis Donahue Jeff Lapak Hayden Haynes Dan Nemr University of New Hampshire University of New Hampshire University of New Hampshire University of New Hampshire University of New Hampshire 2.5, 5 and 10 Gigabit Ethernet Testing Services 4 Clause 126 PMA Test Suite v1.2

5 The University of New Hampshire INTRODUCTION The University of New Hampshire s (IOL) is an institution designed to improve the interoperability of standards based products by providing an environment where a product can be tested against other implementations of a standard. This particular suite of tests has been developed to help implementers evaluate the functionality of the Physical Medium Attachment (PMA) sublayer of their 2.5G/5GBASE-T products. These tests are designed to determine if a product conforms to specifications defined in the IEEE standard. Successful completion of all tests contained in this suite does not guarantee that the tested device will operate with other devices. However, combined with satisfactory operation in the IOL s interoperability test bed, these tests provide a reasonable level of confidence that the Device Under Test (DUT) will function properly in many 2.5G/5GBASE-T environments. The tests contained in this document are organized in such a manner as to simplify the identification of information related to a test, and to facilitate in the actual testing process. Tests are organized into groups, primarily in order to reduce setup time in the lab environment, however the different groups typically also tend to focus on specific aspects of device functionality. A three-part numbering system is used to organize the tests, where the first number indicates the clause of the IEEE standard on which the test suite is based. The second and third numbers indicate the test s group number and test number within that group, respectively. This format allows for the addition of future tests to the appropriate groups without requiring the renumbering of the subsequent tests. The test definitions themselves are intended to provide a high-level description of the motivation, resources, procedures, and methodologies pertinent to each test. Specifically, each test description consists of the following sections: Purpose The purpose is a brief statement outlining what the test attempts to achieve. The test is written at the functional level. References This section specifies source material external to the test suite, including specific subclauses pertinent to the test definition, or any other references that might be helpful in understanding the test methodology and/or test results. External sources are always referenced by number when mentioned in the test description. Any other references not specified by number are stated with respect to the test suite document itself. Resource Requirements The requirements section specifies the test hardware and/or software needed to perform the test. This is generally expressed in terms of minimum requirements, however in some cases specific equipment manufacturer/model information may be provided. Last Modification This specifies the date of the last modification to this test. Discussion The discussion covers the assumptions made in the design or implementation of the test, as well as known limitations. Other items specific to the test are covered here. Test Setup The setup section describes the initial configuration of the test environment. Small changes in the configuration should not be included here, and are generally covered in the test procedure section, below. Procedure The procedure section of the test description contains the systematic instructions for carrying out the test. It provides a cookbook approach to testing, and may be interspersed with observable results. Observable Results This section lists the specific observables that can be examined by the tester in order to verify that the DUT is operating properly. When multiple values for an observable are possible, this section provides a short discussion on how to interpret them. The determination of a pass or fail outcome for a particular test is generally based on the successful (or unsuccessful) detection of a specific observable. Possible Problems 2.5, 5 and 10 Gigabit Ethernet Testing Services 5 Clause 126 PMA Test Suite v1.2

6 The University of New Hampshire This section contains a description of known issues with the test procedure, which may affect test results in certain situations. It may also refer the reader to test suite appendices and/or whitepapers that may provide more detail regarding these issues. 2.5, 5 and 10 Gigabit Ethernet Testing Services 6 Clause 126 PMA Test Suite v1.2

7 The University of New Hampshire GROUP 1: PMA TRANSMITTER ELECTRICAL SPECIFICATIONS Overview: This group of tests verifies several of the electrical specifications of the 2.5G/5GBASE-T Physical Medium Attachment sublayer outlined in Clause 126 of the IEEE Std bz Scope: All of the tests described in this section are currently under development at the University of New Hampshire. 2.5, 5 and 10 Gigabit Ethernet Testing Services 7 Clause 126 PMA Test Suite v1.2

8 Test Maximum Output Droop The University of New Hampshire Purpose: To verify that the transmitter output level does not droop more than the maximum specified amount. References: [1] IEEE Std bz -2016, subclause , Test modes [2] IEEE Std bz -2016, subclause , Test fixtures [3] IEEE Std bz -2016, subclause , Maximum output droop Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: Reference [1] states that a 2.5G/5GBASE-T device shall implement 7 test modes. These test modes are provided to measure electrical characteristics and verify compliance. Reference [2] defines the test fixture to be used to perform the test. Reference [3] provides a specification for the maximum allowable droop for the transmitter. This test requires the device under test (DUT) to operate in transmitter test mode 6. While in test mode 6, the DUT shall generate a sequence of symbols followed by symbols continually from all four transmitters with the THP turned off. Test Setup: Refer to test suite appendix Test Procedure: 1. Configure the DUT so that it is operating in transmitter test mode Connect pair BI_DA from the MDI to test fixture Find a rising-edge zero-crossing in the waveform (the reference). 4. Measure the amplitude of the waveform at 10 ns after the reference zero-crossing (V 10). 5. For 2.5GBASE-T operation, measure the amplitude of the waveform at 330 ns after the reference zerocrossing (V 90). For 5GBASE-T operation, measure the amplitude of the waveform at 170 ns after the reference zero-crossing (V 90). 6. Compute the droop between V 10 and V Repeat using a falling edge reference. 8. Repeat steps 2 through 7 for pairs BI_DB, BI_DC, and BI_DD. Observable Results: For 2.5GBASE-T operation a. The magnitude of both the positive droop shall be less than 17.5% for all pairs. b. The magnitude of both the negative droop shall be less than 17.5% for all pairs. For 5GBASE-T operation a. The magnitude of both the positive droop shall be less than 12.5% for all pairs. b. The magnitude of both the negative droop shall be less than 12.5% for all pairs. Possible Problems: None. 2.5, 5 and 10 Gigabit Ethernet Testing Services 8 Clause 126 PMA Test Suite v1.2

9 Test Transmitter Nonlinear Distortion The University of New Hampshire Purpose: To verify that the output of the transmitter conforms to the transmitter linearity mask. References: [1] IEEE Std bz -2016, subclause , Test Modes [2] IEEE Std bz -2016, subclause , Test Fixtures [3] IEEE Std bz -2016, subclause , Transmitter nonlinear distortion Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: Reference [1] states that a 2.5G/5GBASE-T device shall implement 7 test modes. These test modes are provided to measure electrical characteristics and verify compliance. Reference [2] defines the test fixture to be used to perform the test. For both 2.5GBASE-T and 5GBASE-T operation the transmitter nonlinear distortion shall be greater than: SFDR min {52, 58 20log 10 ( f )} Eq Where f is the maximum frequency of the two test tones in MHz and SFDR is the ratio in db of the minimum RMS value of either input tone to the RMS value of the worst intermodulation product in the frequency range of 1 to 100 MHz for 2.5GBASE-T and 1 to 200 MHz for 5GBASE-T. Reference [3] provides a specification for the linearity of the transmitter. 2.5GBASE-T operational devices are required to meet an extra requirement: SFDR min {52, 58 20log 10 ( f )} Eq Where f is the maximum frequency of the two test tones in MHz and SFDR is the ratio in db of the minimum RMS value of either input tone to the RMS value of the worst intermodulation product in the frequency range of 1 to 100 MHz. Test Setup: Refer to test suite appendix Test Procedure: 1. Configure the DUT so that it is operating in transmitter test mode Connect pair BI_DA from the MDI to test fixture Capture the spectrum of the transmitted test mode waveform using a spectrum analyzer. 4. Compute the SFDR of the waveform. 5. Repeat steps 3 through 4 for the remainder of the test tones as specified in reference [1]. 6. Repeat steps 2 through 5 for pairs BI_DB, BI_DC, and BI_DD. Observable Results: For 2.5GBASE-T operation a. The SFDR of the transmitter shall meet Equation for frequencies of 1 to 100 MHz. b. In Transmitter Nonlinear Distortion Setup 2, while at 0 db PBO, the SFDR of the transmitter shall also meet Equation for frequencies of 1 to 100 MHz. For 5GBASE-T operation a. The SFDR of the transmitter shall meet Equation for frequencies of 1 to 200 MHz. Possible Problems: None. 2.5, 5 and 10 Gigabit Ethernet Testing Services 9 Clause 126 PMA Test Suite v1.2

10 Test Transmitter Timing Jitter The University of New Hampshire Purpose: To verify that the transmitter timing jitter of the PMA is within the conformance limits. References: [1] IEEE Std bz -2016, subclause , Test modes [2] IEEE Std bz -2016, subclause , Test Fixtures [3] IEEE Std bz -2016, subclause , Transmitter timing jitter Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: Reference [1] states that a 2.5G/5GBASE-T device shall implement 7 test modes. These test modes are provided to measure electrical characteristics and verify compliance. Reference [2] define the test fixture to be used to perform the test. Reference [3] provides a specification for the transmitter timing jitter. Case 1 MASTER transmitter timing jitter When in test mode 2, the PHY transmits symbols followed by 2 16 symbols continually with the THP turned off and with no power backoff. In this mode, the transmitter output should be a 50 MHz signal for 2.5GBASE-T operation or a 100 MHz signal for 5GBASE-T operation, and the RMS period jitter measured at the PHY MDI output shall be less than 10.0 ps for 2.5GBASE-T operation and 7.2 ps for 5GBASE-T operation. The RMS period jitter is measured as per the test configuration shown in Figure over an integration time interval of 4 ms +/- 10% for 2.5GBASE-T operation and 2 ms +/- 10% for 5GBASE-T operation. Case 2 SLAVE transmitter timing jitter For a PHY supporting loop timing mode, the MASTER PHY is set to test mode 1 and the SLAVE PHY is in test mode 3. The MASTER PHY transmits the PMA training pattern (PRBS 33) to the SLAVE PHY on pairs A, B and C, and the SLAVE must synchronize its transmit clock to the signals received from the MASTER PHY. The RMS period jitter measured at the SLAVE PHY MDI output shall be less than 10.0 ps for 2.5GBASE-T operation and 7.2 ps for 5GBASE-T operation. The RMS period jitter is measured as per the test configuration shown in Figure over an integration time interval of 4 ms +/- 10% for 2.5GBASE-T operation and 2 ms +/- 10% for 5GBASE-T operation. Test Setup: Refer to test suite appendix Test Procedure: 1. Configure the DUT so that it is operating in transmitter test mode Connect pair BI_DA from the MDI to test fixture For 2.5GBASE-T operation, capture 4ms±10% using a sample size of 200,000±20,000. For 5GBASE-T operation, capture 2ms±10% using a sample size of 200,000±20, Calculate the RMS period jitter according to equation in reference [3]. 5. Repeat steps 2 through 4 for pairs BI_DB, BI_DC, and BI_DD. 6. If PHY supports loop timing, configure the DUT so that the MASTER PHY is operating in transmitter test mode 1, SLAVE PHY is operating in transmitter test mode 3, and repeat steps 2 through 5. Observable Results: Case 1 MASTER transmitter timing jitter For 2.5GBASE-T operation a. The RMS period jitter measured at the MDI output should not exceed 10.0 ps for all pairs. 2.5, 5 and 10 Gigabit Ethernet Testing Services 10 Clause 126 PMA Test Suite v1.2

11 The University of New Hampshire For 5GBASE-T operation a. The RMS period jitter measured at the MDI output should not exceed 7.2 ps for all pairs. Case 2 SLAVE transmitter timing jitter For 2.5GBASE-T operation b. The RMS period jitter measured at the MDI output should not exceed 10.0 ps for all pairs. For 5GBASE-T operation b. The RMS period jitter measured at the MDI output should not exceed 10.0 ps for all pairs. Possible Problems: None. 2.5, 5 and 10 Gigabit Ethernet Testing Services 11 Clause 126 PMA Test Suite v1.2

12 The University of New Hampshire Test Transmitter Power Spectral Density and Power Level Purpose: To verify the transmitter power level and power spectral density are within the conformance limits. References: [1] IEEE Std bz -2016, subclause , Test modes [2] IEEE Std bz -2016, subclause , Test Fixtures [3] IEEE Std bz -2016, subclause , Transmitter PSD and power level [4] IEEE Std bz -2016, figure , Transmitter PSD mask Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: Reference [1] states that a 2.5G/5GBASE-T PHY shall implement 7 test modes. These test modes are provided to measure electrical characteristics and verify compliance. Reference [2] discusses the operation of a device while in test mode 5. Reference [1] defines the operation of a device while in test mode 5, while reference [3] provides a specification for the transmitter power spectral density and power level. Reference [4] provides the transmitter power spectral density mask. In test mode 5, the device shall transmit as in normal operation with power backoff disabled. The transmit power shall be between 1.0dBm and 3.0dBm and the power spectral density, measured into 100, shall fit within the upper and lower masks of [4]. Test Setup: Refer to test suite appendix Test Procedure: 1. Configure the DUT so that it is operating in transmitter test mode Connect pair BI-DA to transmitter test fixture Capture the spectrum of the transmitted test mode waveform using a spectrum analyzer. 4. For enhanced accuracy, repeat step 3 multiple times and average the voltages measured at each point. 5. Compute the transmit power and power spectral density. 6. Repeat steps 2 through 5 for pairs BI_DB, BI_DC, and BI_DD. Observable Results: For 2.5GBASE-T operation a. The transmit power shall be between 1.0dBm and 3.0dBm for all pairs. b. The power spectral density of the transmitter output while operating in test mode 5 shall fit within the transmitter power spectral density mask shown in figure for all pairs. For 5GBASE-T operation a. The transmit power shall be between 1.0dBm and 3.0dBm for all pairs. b. The power spectral density of the transmitter output while operating in test mode 5 shall fit within the transmitter power spectral density mask shown in figure for all pairs. Possible Problems: None. 2.5, 5 and 10 Gigabit Ethernet Testing Services 12 Clause 126 PMA Test Suite v1.2

13 Test Transmit Clock Frequency The University of New Hampshire Purpose: To verify that the frequency of the transmit clock is within the conformance limits References: [1] IEEE Std bz -2016, subclause Transmit clock frequency Resource Requirements: Refer to appendix Last Modification: March 15, 2017 Discussion: Reference [1] states that all 2.5GBASE-T devices must have a symbol transmission rate of MHz ± 50 ppm and all 5GBASE-T devices must have a symbol transmission rate of MHz ± 50 ppm while operating in Master timing mode. When the transmitter is in the LPI transmit mode or when the receiver is in the LPI receive mode the transmitter clock short term rate variation shall be less than 0.1 ppm/second. The reference clock used in this test is the one obtained in test , Transmitter Timing Jitter. The frequency of this clock extracted from the transmitted waveform shall have a base frequency of 200 MHz ± 50ppm for 2.5GBASE-T devices and 400 MHz ± 50ppm for 5GBASE-T devices. Test Setup: Refer to test suite appendix Procedure: 1. Configure the DUT for test mode 2 operation. 2. Using a narrow-bandwidth PLL, extract the clock frequency from the transmitted symbols. 3. Measure the frequency of the transmit clock. Observable Results: For 2.5GBASE-T operation a. The transmit clock generated by the DUT shall have a frequency of 200MHz ± 50ppm. For 5GBASE-T operation a. The transmit clock generated by the DUT shall have a frequency of 400MHz ± 50ppm. Possible Problems: None. 2.5, 5 and 10 Gigabit Ethernet Testing Services 13 Clause 126 PMA Test Suite v1.2

14 The University of New Hampshire GROUP 2: PMA RECEIVER ELECTRICAL SPECIFICATIONS Overview: This group of tests verifies several of the electrical specifications of the 2.5G/5GBASE-T Physical Medium Attachment sublayer outlined in Clause 126 of the IEEE Std bz Scope: All of the tests described in this section are currently under development at the University of New Hampshire. 2.5, 5 and 10 Gigabit Ethernet Testing Services 14 Clause 126 PMA Test Suite v1.2

15 Test Bit Error Rate Verification The University of New Hampshire Purpose: To verify that the device under test (DUT) can maintain low bit error rate in the presence of the worst-case input signal-to-noise ratio. References: [1] IEEE Std bz -2016, subclause Receiver differential input signals [2] IEEE Std bz -2016, subclause 126.7, Link Segment Characteristics [3] IEEE Std bz -2016, subclause Transmitter Electrical Specifications Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: The operation of the 2.5G/5GBASE-T PMA sublayer is defined in [1], to operate with a BER of 10-12, as specified in [1], over a worst case channel, as defined in [2]. This test shall verify a 7.8x10-9 Frame Error Rate using the maximum cable length of 100m. The transmit station is configured to meet the requirements set in [3]. The transmit settings utilize the lowest transmit amplitude possible. The device shall operate over both cable types as defined in [2]. Test Setup: Refer to test suite appendix Procedure: 1. Connect the transmit station to the DUT across a 100m Category 5e cable plant. 2. Configure the transmit station such that it is configured to the lowest amplitude settings while still meeting the requirements defined in [3]. 3. The test station shall send 800 octet frames (for a 7.8x10-9 FER) and the monitor will count the number of packet errors. Observable Results: The DUT shall operate at a FER of 7.8x10-9 for any iteration. Possible Problems: None 2.5, 5 and 10 Gigabit Ethernet Testing Services 15 Clause 126 PMA Test Suite v1.2

16 Test Receiver Frequency Tolerance The University of New Hampshire Purpose: To verify that the device under test (DUT) can maintain low bit error rate in the presence of the worst case input signal-to-noise ratio. References: [1] IEEE Std bz -2016, subclause Receiver differential input signals [2] IEEE Std bz -2016, subclause Link Segment Characteristics [3] IEEE Std bz -2016, subclause Transmitter Electrical Specifications [4] IEEE Std bz -2016, subclause Receiver frequency tolerance Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: The operation of the 2.5G/5GBASE-T PMA sublayer is defined in [1], to operate with a BER of 10-12, as specified in [1], over a worst case channel, as defined in [2]. This test shall verify a 7.8x10-9 Frame Error Rate. 2.5GBASE-T devices are also required to properly receive incoming data with symbol rates ranging from 200 MHz ± 50 ppm and 5GBASE-T devices are also required to properly receive incoming data with symbol rates ranging from 400 MHz ± 50 ppm as defined in [4]. Test Setup: Refer to test suite appendix Procedure: 1. Connect the transmit station to the DUT across a 100m Category 5e cable plant. 2. For 2.5GBASE-T Operation: Configure the transmit station such that it is configured to the lowest amplitude settings while still meeting the requirements defined in [3] sending frames at a symbol rate of 200 MHz + 50 ppm. For 5GBASE-T Operation: Configure the transmit station such that it is configured to the lowest amplitude settings while still meeting the requirements defined in [3] sending frames at a symbol rate of 400 MHz + 50 ppm. 3. For 2.5GBASE-T Operation: Repeat steps 1 and 2 with the transmit station sending frames at a symbol rate of 200 MHz - 50 ppm. For 5GBASE-T Operation: Repeat steps 1 and 2 with the transmit station sending frames at a symbol rate of 400 MHz - 50 ppm. 4. The test station shall send 800 octet frames (for a 7.8x10-9 FER) and the monitor will count the number of packet errors. Observable Results: The DUT shall operate at a FER of 7.8x10-9 for any iteration. 2.5, 5 and 10 Gigabit Ethernet Testing Services 16 Clause 126 PMA Test Suite v1.2

17 Test Alien Crosstalk Noise Rejection The University of New Hampshire Purpose: To verify that the device under test (DUT) can maintain low bit error rate in the presence of the worst-case input signal-to-noise ratio. References: [1] IEEE Std bz -2016, subclause Receiver differential input signals [2] IEEE Std bz -2016, subclause 126.7, Link Segment Characteristics [3] IEEE Std bz -2016, subclause Transmitter Electrical Specifications [4] IEEE Std bz -2016, subclause Alien crosstalk noise rejection Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: The operation of the 2.5G/5GBASE-T PMA sublayer is defined in [1], to operate with a BER of 10-12, as specified in [1], over a worst case channel, as defined in [2]. This test shall verify a 7.8x10-9 Frame Error Rate using a cable length of up to 100 meters. The transmit station is configured to transmit the worst case rise time and output amplitude, while still meeting the requirements set in [3]. The transmit settings utilize the lowest transmit amplitude possible. In addition to the worst case transmitter and channel settings, 2.5G/5GBASE-T devices are also required to reject alien crosstalk noise introduced with couplers at the MDI inputs. The test channel shall be shortened to compensate for the insertion loss introduced by the couplers and baluns required for the test. Test Setup: Refer to test suite appendix Procedure: 1. Configure the transmit station such that it generates the slowest worst-case rise time and output amplitude, while maintaining the minimum electrical requirements discussed in [3] with wideband Gaussian noise sources introduced as defined in [4]. 2. The test station shall send 800 octet frames (for a 7.8x10-9 FER) and the monitor will count the number of packet errors. Observable Results: For 2.5GBASE-T operation: a. The DUT shall operate at a FER of 7.8x10-9 for all pairs with a noise source whose power spectral density is -125 dbm/hz from 10 to 100 MHz. For 5GBASE-T operation: a. The DUT shall operate at a FER of 7.8x10-9 for all pairs with a noise source whose power spectral density is -137 dbm/hz from 10 to 200 MHz. Possible Problems: None 2.5, 5 and 10 Gigabit Ethernet Testing Services 17 Clause 126 PMA Test Suite v1.2

18 The University of New Hampshire GROUP 3: PMA IMPEDANCE SPECIFICATIONS Overview: This group of tests verifies several of the electrical specifications of the 2.5G/5GBASE-T Physical Medium Attachment sublayer outlined in Clause 126 of the IEEE Std bz Scope: All of the tests described in this section are currently under development at the University of New Hampshire. 2.5, 5 and 10 Gigabit Ethernet Testing Services 18 Clause 126 PMA Test Suite v1.2

19 Test MDI Return Loss The University of New Hampshire Purpose: To measure the return loss at the MDI for all four channels References: [1] IEEE Std bz -2016, subclause MDI return loss. [2] IEEE Std bz -2016, subclause Test modes Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: The MDI on a 2.5G/5GBASE-T device compliant with the IEEE Std bz shall ideally have a differential impedance of 100. Any difference between the impedance of the MDI and the impedance of the connector and cable results in reflections of the transmitted signals. Because the impedances can never be precisely 100, and because the termination impedance varies with frequency, some limited amount of reflections must be allowed. Return loss is a measure of the signal power that is reflected due to the impedance mismatch. [1] specifies that the reflected power at the MDI must be at least: 16 1 f 40 RL { log 10 (f 40) 40 < f 250 (db) Eq This return loss must be maintained when connected to cabling with a characteristic impedance of 100, and while transmitting data or control symbols. Test Setup: Refer to test suite appendix Procedure: 1. Configure the DUT for test mode 5 operation. 2. Connect pair BI_DA to the reflection port of a network analyzer. 3. Measure the reflection coefficient at the transmitter in the frequency range of 1.0 MHz to 250 MHz. 4. Compute the Return Loss for a Z S of Repeat above steps for the BI_DB, BI_DC, and BI_DD pairs. Observable Results: a. The return loss measured at each MDI shall be greater than Equation , 5 and 10 Gigabit Ethernet Testing Services 19 Clause 126 PMA Test Suite v1.2

20 Test MDI impedance balance The University of New Hampshire Purpose: To verify that the common-mode to differential-mode impedance balance of the TD circuit is greater than the specified limit. References: [1] IEEE Std bz -2016, subclause MDI impedance balance [2] IEEE Std bz -2016, subclause Test modes Resource Requirements: Refer to test suite appendix Last Modification: March 15, 2017 Discussion: The impedance balance is defined as the S parameter measurement of Sdc11 in db at the MDI. The impedance balance may be measured with a mixed mode four port network analyzer capable of measuring the common-mode voltage and differential mode voltage of a balanced port. Impedance balance is the S parameter measurement of Sdc11 in db at the MDI where two ports of the four port network analyzer are connected between two MDI contacts used by a duplex link channel and these two ports are configured as a single balanced port. For this test the PHY ground is connected to the network analyzer ground. The other two ports of the network analyzer are unconnected. The network analyzer should be capable of measuring Sdc11 to at least 60 db and should use a differential input impedance of 100Ω and a common-mode impedance of 75Ω. During the test the PHY is connected to the MDI as in normal operation. The impedance balance shall be greater than: 48 1 f 30 Bal(f) { log 10 (f 50) 30 < f 250 (db) Eq Test Setup: Connect the devices as shown in figure Procedure: 1. Configure the DUT for test mode 5 operation. 2. Connect pair BI_DA to the reflection port of a network analyzer. 3. Measure the reflection coefficient at the transmitter in the frequency range of 1.0 MHz to 250 MHz. 4. Compute the Return Loss for a Z S of Repeat above steps for the BI_DB, BI_DC, and BI_DD pairs. Observable Results: a. The impedance balance shall be greater than Equation , 5 and 10 Gigabit Ethernet Testing Services 20 Clause 126 PMA Test Suite v1.2

21 The University of New Hampshire APPENDIX: TEST SETUPS Overview: The appendices contained in this section are intended to provide additional low-level technical details pertinent to specific tests defined in this test suite. Test suite appendices often cover topics that are beyond the scope of the standard, but are specific to the methodologies used for performing the measurements covered in this test suite. This may also include details regarding a specific interpretation of the standard (for the purposes of this test suite), in cases where a specification may appear unclear or otherwise open to multiple interpretations. Scope: Test suite appendices are considered informative, and pertain only to tests contained in this test suite. This is considered a work in progress. 2.5, 5 and 10 Gigabit Ethernet Testing Services 21 Clause 126 PMA Test Suite v1.2

22 Test Setup #1 Test Maximum Output Droop Test Transmit Timing Jitter Master Jitter Test Transmit Clock Frequency The University of New Hampshire Test Setup #2 Test Transmitter Linearity Test Transmitter Power Spectral Density Figure A-1: Test Setup #1 Figure A-2: Test Setup #2 Test Setup #3 Test Transmit Timing Jitter Slave Jitter 2.5, 5 and 10 Gigabit Ethernet Testing Services 22 Clause 126 PMA Test Suite v1.2

23 The University of New Hampshire Figure A-3: Test Setup #3 Test Setup #4 Test MDI Return Loss Figure A-4: Test Setup #4 2.5, 5 and 10 Gigabit Ethernet Testing Services 23 Clause 126 PMA Test Suite v1.2

24 The University of New Hampshire Port A CAT6A Jack Female BI_DA+ SMA SMA BI_DD- BI_DA- SMA SMA BI_DD+ SMA SMA SMA SMA BI_DB+ BI_DB- BI_DC+ BI_DC- Figure A-5: Test Jig #1 Port B Port A CAT6A Jack Female CAT6A Jack Female dB -15dB -15dB SMA SMA BI_DD- BI_DD+ -15dB -15dB -15dB Figure A-6: Test Jig #2 2.5, 5 and 10 Gigabit Ethernet Testing Services 24 Clause 126 PMA Test Suite v1.2